The subject matter relates generally to controlling alternating current power lines.
Alternating current power lines convey power from a power supply to a load. Circuit breakers (or relays) are often used to control the power that is supplied to the load. The current flowing through the power line is primarily alternating current (AC), but some unwanted DC current (called DC offset) may appear along the power line. For example, one or more fault events may occur that inject a DC offset current into the power line. Depending on different factors, the DC offset current may cause unnecessary power consumption, load failure, continuous arc faulting, mechanical and/or thermal stresses, or other unwanted circuit conditions. It may be desirable to break the circuit and/or notify an operator when the DC offset current passes a designated threshold.